There are cases where communication devices and transmission apparatuses (hereinafter collectively referred to as “communication devices”) such as network switches and servers are connected to other communication devices via communication cables. For example, a communication module provided at one end of a communication cable is connected to one communication device, and a communication module provided at the other end of the communication cable is connected to the other communication device. To be specific, one communication module is inserted in a slot provided in a front panel, a rear panel, or the like of one communication device, and the other communication module is inserted in a slot provided in a front panel, a rear panel, or the like of the other communication device. The communication module inserted in each slot is connected to a connector provided at an end of the slot. In the following description, the front panel, the rear panel, or the like of the communication device, provided with the slot for insertion or removal of the communication module may be collectively referred to as a “panel” in some cases.
Pull tabs are provided on casings of some communication modules, and when the pull tab is pulled by pinching an end of the pull tab, the communication module is pulled out from the slot.
In contrast, when a communication module is inserted into the slot, the communication module is inserted therein by pinching its casing. In many cases, a tip of a thumb is placed on one side surface of the casing, and then, a tip of an index finger is placed on the other side surface of the casing to pinch the casing from both sides.
However, a plurality of slots are provided adjacent to each other in the panel. Accordingly, in an attempt to insert a communication module into a slot, another communication module has already been inserted in a slot adjacent to this slot, in some cases. Under such circumstances, the existing communication module which have been inserted in the adjacent slot become an obstacle, and it may be difficult or impossible to insert the communication module to be newly installed into the intended slot by pinching the casing thereof. Therefore, the communication module may be inserted into the slot by holding the communication cable extending from the casing rearward, instead of the casing. (Japanese Patent No. 5254852)